Dewatering press



Sept. 10, 1968 D. B. VINCENT 3,400,654

DEWA'IERING PRESS Filed Oct. 20, 1966 2 Sheets-Sheet 1 I N VEN TOR.

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DEWATERING PRESS Filed Oct. 20, 1966 2 Sheets-Sheet 2 IN VEN TOR. JA /W62 .5. W/vcwr BY &4W,% M

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United States Patent 3,400,654 DEWATERING PRESS Daniel Boscawen Vincent, 2608 Watrous St, Tampa, Fla. 33609 Filed Oct. 20, 1966, Ser. No. 588,093 Claims. (Cl. 100--148) This invention relates to a dewatering press of the general type disclosed in applicants U.S. Patent No. 3,003,- 412, and more particularly, to an improvement in such devices wherein a means is provided to eliminate the problem of effectively moving a press cake from the outlet of the machine.

In the operation of presses such as the one illustrated in U.S. Patent No. 3,003,412, certain problems have developed when substances of a nonuniform viscosity are being pressed. While it is desirable to have a firm press cake at the outlet, frequently, when non-uniform substances are being pressed, a hard, rather than firm, press cake forms on one side of the frusto-conical element at the outlet aperture between the element and the flared outlet member. When this press cake is followed by a mass of material which is more fluid, the hard press cake is not moved entirely out of the way and unpressed material then readily fiows from the other side of the element, causing a pressure loss within the press which retards the amount of liquid removed from the material. In the prior art, this situation usually necessitates a work stoppage during which the frusto-conical element is moved away from the flared member; the outlet is cleared and then, the frusto-conical element is moved back to its normal pressing position.

In some of the prior art presses, this difiiculty has been partially overcome by connecting the frusto-conical element to the screw conveyor drive shaft so that the element will rotate along with, and at the same rate as, the screw conveyor. However, in presses having this modification, such as U.S. Patent No. 3,003,412, it has been necessary to stop the press while the frusto-conical element is connected to the drive shaft. Also, in many instances with the element rotating at the same rate as the screw conveyor, the press case moves too rapidly from the machine preventing the formation of a firm press cake and again unpressed material readily flows from the outlet with a resulting pressure drop within the press.

The present invention solves the above-mentioned problems in the prior art by having a means for rotating the frusto-conical element at a rate substantially slower than the rate of the screw conveyor whereby the press cake is moved from the outlet at a rate such that a firm, but not hard, press cake is formed with no significant pressure drop occurring within the machine. Also, the preferred form of the improved press has a means for starting and stopping the rotation of the element without having to stop the screw conveyor. Thus, not only is the problem of pressure drop within the machine corrected, but also, there is no need to back off the element from the fiared member or stop the press so that the outlet can be cleared of an obstructing press cake.

The preferred means contemplated for carrying out the objects of the invention includes a frusto-conical element slidably mounted on the screw conveyor drive shaft of the press adjacent the hollow flared outlet member of the press. The frusto-conical element is provided with a means for reciprocating the element toward and away from the flared outlet member and a means for driving the frustoconical element at a rate substantially slower than that of the screw conveyor. In the preferred form, the means for driving the frusto-conical element includes an independently actuated electric motor, variable speed reducer and suitable drive train operatively inter-connecting the 3,400,654 Patented Sept. 10, 1968 electric motor and the reducer with the frusto-conical element.

Other objects and advantages of the invention will become more apparent from the following description when taken in connection with the accompanying drawings in which:

FIGURE 1 is a fragmentary side elevation of the press;

FIGURE 2 is an enlarged elevation partially in section showing the preferred form of the invention;

FIGURE 3 is an elevation of a modified form of the invention, partially in section;

FIGURE 4 is an elevational view of the modified form of the invention taken On line 44 of FIGURE 3.

Referring now to FIGURES l and 2 of the drawings, numeral 20 generally indicates the preferred form of the driving means for the apertured, frusto-conical element 40 shown in relation to the main portion of the dewatering press generally indicated by numeral 10. As illustrated in FIGURES 1 and 2, the drive means 20 and frustoconical element 40 are shown with the frusto-conical element 40 in its retracted position relative to the apertured, outwardly flaring, hollow member 11, which is disposed at the outlet of apertured drum 12.

A driven shaft 16 having a screw conveyor 17 thereon is suitably coaxially journalled within the drum 12 and extends through the outlet member 11 and is supported at its outer end in bearing 18 which is suitably mounted on a stationary support member 19. Shaft 16 also serves as a support for frusto-conical member 40, a sprocket 32 and a backing plate 33 all of which are rotatably and slidably mounted on the shaft between bearing 18 and the outlet of drum 12.

The frusto-conical element 40 preferably is apertured and may be arranged on shaft 16 by means of a spiderlike frame 41 having a collar 42 at the forward end thereof slidably and rotatably embracing the shaft. A suitable means such as screw 43 connects the element 40 to an axial rib of the frame 41.

The frusto-conical element 40 is connected to the driving sprocket 32 by means of studs 44. The studs 44 have opposite threads on either end so that they may be threaded into the frame 41 and sprocket 32 at the same time. Also, the studs are of a suitable length to keep the frame 41 of the frusto-conical member and adjacent side of sprocket 32 axially spaced at distance sufficient to prevent drain 15 from being obstructed when the frusto-conical element 40 is in its extended or retracted position.

Frusto-conical element 40, sprocket 32 and the backing plate 33, which is fastened to sprocket 32 by bolts 37, are slidably moved on shaft 16 toward and away from outlet member 11 by means of a reciprocating piston within cylinder 81. The cylinder 81 is connected to a suitable source of pressurized fluid and has a control means, not shown, for alternately pressurizing the cylinder 81 on opposite sides of piston 80 to move the piston 80 toward or away from the outlet member 11. Piston 80 is connected to a vertical plate 83 by means of a rod 84. Plate 83 is in turn connected to a ring member 34 by means of rods 85 which have sleeves 86 thereon to keep the plate 83 and ring member 34 suitably spaced. Ring member 34 abuts backing plate 33 and is held in abutting relation with the backing plate 33 by means of retaining ring 35 which is attached to the backing plate 33 by bolts 36. The retaining ring 35 leaves some clearance between the ring member 34 and the backing plate 33 and thus permits relative rotation between the backing plate 33 and the ring member 34. Also, of course, when the frusto-conical element 40 must be drawn away from the outlet member 11, the retaining ring 35 prevents the ring member 34 from pulling away from the backing member 33 as the piston 80 is moved outwardly.

Sprocket 32 and the frusto-conical element 40 are driven by means of a motor 21 through a gear unit 29 both of which are suitably mounted on a plate 100 which is connected near the end to vertical plate 83 by some suitable means so that the motor 21 and gear unit 29 move axially with the sprocket 32 and frusto-conical member 40. Plate 100 is also supported at its other end by a bracket 101 mounted on ring member 34.

In the preferred form of the invention, motor 21 is provided with an off/on switch 102 and is threadably mounted on a rod 22 by brackets 23. Rod 22 is provided with a wheel 25 and is journalled in a pair of brackets 103 which are mounted on plate 100. Thus, by turning wheel 25 on the end of rod 22, motor 21 may be moved toward or away from gear unit 29.

In the preferred form, gear unit 29 and motor 21 are operatively inter-connected by a belt 27 and pulleys 2S and 26 attached to gear unit 29 and motor 21, respectively. Pulley 26 is a split pulley commonly called a reeves pulley, the sides of which spread apart, reducing the pulleys effective diameter when additional tension is imparted to belt 27 by moving motor 21 and, more specifically, pulley 28, away from gear unit 29. As the sides of the pulley move apart or move together and the effective diameter of pulley 26 changes, the rate at which the pulley 28 is driven varies.

Gear unit 29 has a sprocket 30 mounted on an output shaft 39 which is operatively connected to sprocket 32 by means of a chain 31. The output shaft 39 of housing 29 is mounted with its axis perpendicular to the axis of the input shaft 38 on which pulley 28 is mounted and any suitable gearing means may be provided Within housing 29 connecting the input and output shafts.

Although, as described above, the preferred form of the invention utilizes a reeves pulley arrangement for varying the rate at which frusto-conical element 40 is driven, any suitable drive train may be used which permits the frusto-conical element 40 to be driven at a selected rate. For instance, gear unit 29 may be provided with suitable gearing to selectively vary the rate of output shaft 39 relative to input shaft 38, thus enabling the rate of rotation of element 40 to be effectively controlled. Preferably, the rate at which element 40 rotates should vary between 10 and 20 percent of the rate at which shaft 16 is turning. Since the rate of rotation of motor 21 would generally be too great, the output rate of the driving means 20 is suitably reduced through gear unit 29 and sprockets 31 and 32.

In operation, rotation of frusto-conical element 40 may be started or stopped as conditions require by means of switch 102 on motor 21 without stopping the rotation of shaft 16. Also, the rate at which the element 40 is driven may be adjusted by moving the motor 21 toward or away from gear unit 29 which varies the effective diameter of pulley 26 and thereby the rate at which pulley 28 is driven. Thus, should the outlet aperture between element 40 and outlet member 11 start to be come obstructed, the rate at which element 40 is being rotated may be appropriately varied to move the hard press cake from the outlet 11 without stopping the press or causing a pressure drop within the drum 12.

A suitable shield 104 is provided to cover chain 31 and the outlet 11 and element 40 are enclosed in a housing 13 illustrated in FIGURE 2. The housing 13 has an extension 14 in which element 40 is slidably and rotatably received. Extension 14 is provided with a drain 15 for the fluids which pass through the apertures in element 40. Housing 13 is also provided with a suitable means (not shown) for removing the material discharged from the press.

FIGURES 3 and 4 show a modified form of the invention wherein apertured frusto-conical element 40 is driven through a reduction gear train 300 by shaft 16'.

The reduction gear train 300 and element 40' are slidably mounted on shaft 16' and are moved toward and away from outlet member 11 by means of a piston and cylinder arrangement generally indicated at 81 which is the same as the piston and cylinder arrangement 80, 81 of the preferred form of the invention. Plate 204 is suitably connected to the piston of unit 81' and is provided with spacer rods 203 which are threadedly received in lugs 202 on a ring member 200. Thering member 200 is in two sections suitably fastened together by bolts 201, one of which is shown in dotted lines in FIGURE 3, and is slidably received in circumferential grooves 302 and 45' located on the adjacent faces of gear 301 and the frame 41' of frusto-conical element 40, respectively. Thus, when member 200 is moved toward or away from outlet member 11' by rods 203, gear 301 and frustoconical element 40 are also repositioned.

Gear train 300 comprises gear 303, an intermediate gear 304 and an internal gear 301 which is connected to the frame of the frusto-conical element 40 by studs 44'.

Gear 303 has a sleeve with a flange 310 thereon extending from one side and is slidably keyed to shaft 16' by key 305 which is received in groove 306 of gear 303 and groove 307 of the shaft 16'. Gear 303 is connected to gear 301 by means of a snap ring 308 which is received in a groove 309 in gear 301 and engages the side face of flange 310 on gear 303. Ring 308 and flange 310 permit relative rotation between gears 301 and 303 but keep gear 303 in abutting relationship with gear 301 as it is axially moved along shaft 16.

Intermediate gear 304 is mounted on a shaft 400 which is attached to plate 204 at one end and is slidably received in a bearing 401. Gear 304 is made up of two sections of differing diameter with the section of larger diameter 304A engaging gear 303 and the section of lesser diameter 304B drivingly engaging internal gear 301. Gear 304 is slidably mounted on shaft 400 and is caused to move axially in unison with gears 303 and 301 by flanges 311 on gear 303 which extend radially outward past the gear teeth of gear 303 and engage the side walls of the enlarged portion 304A of gear 304.

In operation, frusto-conieal element 40', which is connected to internal gear 301 by studs 44', is driven by shaft 16' through gear train 300. Gear 303, which is directly driven by shaft 16, engages section 304A of intermediate gear 304. Section 304B of intermediate gear 304 which is of a lesser diameter than section 304A drives internal gear 301 which is connected to and rotates with element 40'. Due to the small diameter of section 304B of gear 304 and the large diameter of internal gear 301, the output of gear train 300 is such that the rate of rotation of element 40' is substantially lower than shaft 16'.

In the gear train 300, as shown by the arrows in FIG- URE 4, internal gear 301 and consequently frusto-conical element 40' rotate in a clockwise direction while shaft 16' rotates in a counterclockwise direction. However, since the rotation imparted to the pressed material by the dewatering press is minimal, the direction of rotation of frusto-conical element 40 relative to shaft 16' is immaterial as long as the element 40' rotates substantially slower than shaft 16, preferably between 10 and 20 percent of the rate at which shaft 16 turns.

The modification of FIGURES 3 and 4 is provided with a housing 13' having a suitable means (not shown) for removing the material discharged from outlet 11'. Also, a drain 15 is provided in member 200 for removal of the fluids which pass through element 40'.

While the two forms of the invention have been shown and described, it is to be understood that all suitable modifications and equivalents may be resorted to which fall within the scope of the invention, as claimed.

What is claimed is:

1. A dewatering press comprising: a drum having an outlet; a hollow member disposed at said outlet in substantially coaxial relation to said drum; a driven shaft having screw conveyor means thereon journalled in said drum coaxially therewith and extending through said outlet and said member; an element coaxially disposed on said shaft adjacent to and externally of said hollow member, said element shaped so that it cooperates with the hollow member to form an annular passage at the outlet of the drum and means for rotating said element at a rate substantially less than the rate of the screw conveyor.

2. The dewatering press of claim 1 wherein the element is slidably mounted on said shaft and is provided with means for axially moving the element on said shaft toward or away from said member.

3. The dewatering press of claim 1 wherein the rate at which the element is rotated ranges between and percent of the rate at which said screw conveyor is rotated.

4. The dewatering press of claim 1 wherein the means for rotating said element is a reduction gear train driven by said shaft and connected to said element.

5. A dewatering press comprising: a drum having an outlet; a hollow member disposed at said outlet in substantially coaxial relation to said drum; a driven shaft having screw conveyor means thereon journalled in said drum coaxially therewith and extending through said outlet and said member; an element coaxially disposed on said shaft adjacent to and externally of said hollow member, said element being shaped so that it cooperates with the hollow member to form an annular passage at the outlet of the drum; means other than said driven shaft for rotating said element at selected rates substantially less than the rate of the screw conveyor and means for starting and stopping the element drive means when desired.

6. The dewatering press of claim 5 wherein the element is slidably mounted on said shaft and is provided with means for axially moving the element on said shaft toward or away from said member.

7. The dewatering press of claim 5 wherein the selected rates for driving the element range from 10 to 20 percent of the rate at which the screw conveyor is driven.

8. The dewatering press comprising: an apertured drum having an outlet; an apertured outwardly flaring and hollow member disposed at said outlet in substantially coaxial relation to said drum; a driven shaft having screw conveyor means thereon journalled in said drum coaxially therewith and extending through said outlet and said member; an apertured frusto-conical element coaxially disposed on said shaft adjacent to and externally of said hollow member, said element flaring in the same direction as said member; means other than said driven shaft for rotating said frusto-conical element at selected rates substantially less than the rate of the screw conveyor and means for starting and stopping the frusto-conical element drive means when desired.

9. The dewatering press of claim 8 wherein the frustoconical element is slidably mounted on said shaft and is provided with means for axially moving the element on said shaft toward or away from said member.

10. The dewatering press of claim 8 wherein the selected rates for rotating the frusto-conical element range from 10 to 20 percent of the rate at which the screw conveyor is rotated.

References Cited UNITED STATES PATENTS 1,421,282 6/1922 Meakin 148 1,662,531 3/1928 Meakin 100--150 1,733,381 10/1929 Meakin 100150 X 3,003,412 10/1961 Vincent 100148 X 3,246,594 4/1966 Fisher 100147 X 3,285,163 11/1966 Burner 100-150 X LOUIS O. MAASSEL, Primary Examiner. 

1. A DEWATERING PRESS COMPRISING: A DRUM HAVING AN OUTLET; A HOLLOW MEMBER DISPOSED AT SAID OUTLET IN SUBSTANTIALLY COAXIAL RELATION TO SAID DRUM; A DRIVEN SHAFT HAVING SCREW CONVEYOR MEANS THEREON JOURNALLED IN SAID DRUM COAXIALLY THEREWITH AND EXTENDING THROUGH SAID OUTLET AND SAID MEMBER; AN ELEMENT COAXIALLY DISPOSED ON SAID SHAFT ADJACENT TO AND EXTERNALLY OF SAID HOLLOW MEMBER, SAID ELEMENT SHAPED SO THAT IT COOPERATES WITH THE HOLLOW MEMBER TO FORM AN ANNULAR PASSAGE AT THE OUTLET OF THE DRUM AND MEANS FOR ROTATING SAID ELEMENT AT A RATE SUBSTANTIALLY LESS THAN THE RATE OF THE SCREW CONVERYOR. 